Rubber compositions for vehicles tires may make use of various fillers to impart desirable properties to the rubber composition. The rubber molecules and filler particles may interact through cross-linking. The amount of cross-linking must be controlled, however. Insufficient cross-linking can lead to a rubber composition having poor properties (e.g., abrasion resistance, hardness, etc.) and too much cross-linking can lead to a rubber composition being brittle and hard to process.